Influence of Field-Like Torque in Synchronization of Spin Torque Oscillators

The magnetization dynamics of two parallelly coupled spin torque oscillators, destabilization of steady states, and removal of multistability are investigated by taking into account the influence of field-like torque. It is shown that the existence of such torque can cancel the effect of damping and can, therefore, cause the oscillators to exhibit synchronized oscillations in response to direct current. Furthermore, our results show that the presence of field-like torque enhances the power and Q-factor of the synchronized oscillations. The validity of the above results is confirmed by numerical and analytical studies based on the stochastic Landau-Lifshitz-Gilbert-Slonczewski equation.